Smoking article with improved extinguishment

ABSTRACT

A smoking article (10) comprises a tobacco rod (11) and a filter (12) in axial alignment with the tobacco rod (11). Tipping wrapper (16) circumscribes at least a portion of the filter (12) and at least a portion of the tobacco rod (11) to secure the filter (12) in axial alignment with the tobacco rod (11). The filter (12) comprises a hollow tubular element (13) at the upstream end of the filter (12) adjacent to the tobacco rod (11) and a first segment of filtration material (15) downstream from and adjacent to the hollow tubular element (13). The tipping wrapper (16) comprises a line of weakness (17) disposed at, or within 4 millimetres upstream of the interface between the hollow tubular element (13) and the tobacco rod (11). The tobacco rod (11), the first segment of filtration material (15) and the inner surface of the hollow tubular element (13) together define a cavity (14). The cavity (14) is designed to receive the lit end of the smoking article (10) and any unburnt tobacco material when the consumer chooses to extinguish the smoking article (10).

This application is a continuation of U.S. application Ser. No.15/736,043 filed Dec. 13, 2017 and which is a U.S. National StageApplication of International Application No. PCT/EP2016/065402, filedJun. 30, 2016, which was published in English on Jan. 5, 2017, asInternational Publication No. WO 2017/001613 A1. InternationalApplication No. PCT/EP2016/065402 claims priority to EuropeanApplication No. 15174662.5, filed Jun. 30, 2015.

The present invention relates to smoking articles (for examplecigarettes). Filter cigarettes typically comprise a rod of tobacco cutfiller surrounded by a paper wrapper and a cylindrical filter aligned inend-to-end relationship with the wrapped tobacco rod, with the filterattached to the tobacco rod by tipping paper. In conventional filtercigarettes, the filter may consist of a plug of cellulose acetate towwrapped in porous plug wrap. Filter cigarettes with multi-componentfilters that comprise two or more segments of filtration material forthe removal of particulate and gaseous components of the mainstreamsmoke are also known.

Generally, a consumer smokes a smoking article until the burning area ofthe tobacco rod (the lit end) reaches the edge of the tipping paper.This means that a small portion of the tobacco (where the tipping paperoverlaps the tobacco rod) still remains unburnt and will continue toburn unless extinguished. Therefore, the consumer extinguishes thesmoking article, typically by holding the filter and pressing the litend of the smoking article against the base of an ashtray or other hardnon-flammable surface. This disrupts the structure of the lit end andprevents oxygen reaching the burning tobacco, and burning usually stopsrapidly. However, in the process of extinguishing the smoking article,the consumer's fingers may come into contact with, or close to, the litend of the smoking article or old ash remaining in the ashtray.

Several solutions have therefore been proposed for extinguishing asmoking article in a safe, hygienic way. For example, it has beenproposed to modify the burning characteristics of the paper surroundingthe tobacco rod at or around its downstream end, so that the cigarettewill effectively self-extinguish when the lit end reaches this modifiedsection. However, in some circumstances, a consumer may wish toextinguish the cigarette before the lit end reaches the modified sectionof the wrapper, and thus need to extinguish the cigarette manually.Furthermore, the modified section may not always extinguish the lit endin a quick and reliable manner. In addition, such an arrangement willstill result in loose ash being left in the ashtray.

An alternative proposed solution is to provide a tube or sleeve that canslide over a smoking article and cover the lit end of the tobacco rod toextinguish the smoking article, after a consumer has finished smokingthe smoking article. However, such tubes can hinder or undesirablyaffect the function of the smoking article during smoking.

It would therefore be desirable to provide a solution for extinguishinga smoking article in safe and hygienic way, without hindering orundesirably affecting the function of the smoking article duringsmoking.

Accordingly, the present invention provides a smoking article comprisinga tobacco rod; a filter in axial alignment with the tobacco rod; and atipping wrapper circumscribing at least a portion of the filter and atleast a portion of the tobacco rod to secure the filter in axialalignment with the tobacco rod, wherein the filter comprises: a hollowtubular element at the upstream end of the filter adjacent to thetobacco rod; and a first segment of filtration material downstream fromand adjacent to the hollow tubular element. It is understood that theinner surface of the hollow tubular element, the downstream end of thetobacco rod and the upstream end of the first segment of filtrationtogether define the boundary of an internal cavity within the filter.

The provision of a hollow tubular element at the upstream end of thefilter, adjacent the tobacco rod allows the consumer to easilyextinguish the smoking article by, for example, holding the filter andpressing the lit end of the smoking article against a hard non-flammablesurface, such as an ashtray. This pushes the lit end of the smokingarticle and any unburnt tobacco into the cavity of the hollow tubularelement. The portion of the tipping paper that circumscribes the tobaccorod and any remaining cigarette paper may also be pushed into the cavityof the hollow tubular element. This can minimise the likelihood of theash or the lit end coming into contact with a consumer's fingers and mayalso reduce the amount of loose material, such as ash, created duringthe act of extinguishing the smoking article. This can also reduce theoxygen supply to the lit end, and thereby improve the rate at which thesmoking article is extinguished.

As used herein, the terms “upstream” and “downstream” are used todescribe relative positions between elements of the filter or smokingarticle in relation to the direction of mainstream smoke as it is drawnfrom a lit end of the smoking article through the filter. Mainstreamsmoke flows generally parallel to the length of the smoking article, inthe longitudinal direction. The transverse direction of the smokingarticle is perpendicular to the longitudinal direction.

As used herein, the term “inner surface” is used to describe the side ofthe hollow tubular element that faces towards the inside of the filter.

As used herein, the term “buckling strength” refers to the axialcompressive load on the smoking article filter at which the filter willcollapse or buckle. This load may be caused by the consumer pressing thelit end of the smoking article against the base of an ashtray or otherhard non-flammable surface.

As used herein, the term “filling power” is used to describe the volumeof space taken up by a given weight or mass of a tobacco material. Thegreater the filling power of a tobacco material, the lower the weight ofthe material required to fill a tobacco rod of standard dimensions. Thevalues of filling power are expressed in terms of corrected cylindervolume (CCV) which is the cylinder volume (CV) of the tobacco materialat a reference moisture level of 12.5 percent oven volatiles. Thecylinder volume (CV) may be determined using a Borgwaldt densimeter DD60or DD60A type fitted with a measuring head for cut tobacco and a tobaccocylinder container.

Preferably, the hollow tubular element has a (wall) thickness (t)perpendicular to the longitudinal direction of the smoking article offrom about 100 micrometers to about 700 micrometers. More preferably,the hollow tubular element has a thickness (t) perpendicular to thelongitudinal direction of the smoking article of from about 150micrometers to about 400 micrometers, and even more preferably fromabout 200 micrometers to about 300 micrometers. In some preferredembodiments, the hollow tubular element has a thickness (t)perpendicular to the longitudinal direction of the smoking article ofabout 250 micrometers.

The provision of a hollow tubular element having a thickness (t)perpendicular to the longitudinal direction of the smoking articlewithin the aforementioned ranges reduces the risk of the hollow tubularelement collapsing or deforming when the consumer extinguishes thesmoking article by, for example, pressing the lit end against a hardnon-flammable surface. Furthermore, this also helps prevent the tobaccoof the tobacco rod from entering the upstream end of the hollow tubularelement before the consumer chooses to extinguish the smoking article.In addition, this provision can help to prevent the first segment offiltration material from entering the downstream end of the hollowtubular element when the consumer extinguishes the smoking article. Theprovision of a hollow tubular element having a thickness (t)perpendicular to the longitudinal direction of the smoking articlewithin the aforementioned range can also ensure that the internal cavityof the hollow tubular element is large enough to receive the lit end ofthe smoking article and any unburnt tobacco, thereby minimising thelikelihood of the ash or the lit end coming into contact with aconsumer's fingers.

Preferably, the hollow tubular element is formed from a material with agrammage of from about 50 grams per square metre to about 250 grams persquare metre, more preferably from about 80 grams per square metre toabout 150 grams per square metre. In certain preferred embodiments, thehollow tubular element is formed from a material with a grammage ofabout 100 grams per square metre.

The provision of a hollow tubular element having a grammage within theaforementioned ranges can increase the buckling strength of the hollowtubular element, which can in turn help to reduce the risk of the hollowtubular element collapsing or deforming when the consumer extinguishesthe smoking article.

Preferably, the hollow tubular element has a length (L) of from about 3millimetres to about 20 millimetres. More preferably, the hollow tubularelement has a length of from about 4 millimetres to about 15millimetres, even more preferably, from about 5 millimetres to about 10millimetres. In some preferred embodiments, the hollow tubular elementhas a length of about 6 millimetres.

The provision of a hollow tubular element having a length greater thanabout 4 millimetres may help enable the internal cavity of the hollowtubular element to be large enough to receive the lit end of the smokingarticle and any unburnt tobacco thereby minimising the likelihood of theash or the lit end coming into contact with a consumer's fingers.

Preferably, the hollow tubular element has a length that is greater thanor equal to the length of the portion of the tipping wrapper thatcircumscribes the tobacco rod. This can ensure that any loose tobaccothat underlies the portion of the tipping wrapper that circumscribes thetobacco rod is able to fit inside the hollow tubular element when thesmoking article is extinguished.

Preferably, the tipping wrapper comprises a line of weakness disposedat, or within 5 mm upstream of the interface between the hollow tubularelement and the tobacco rod, more preferably disposed at, or within 2 mmupstream of, the interface between the hollow tubular element and thetobacco rod. The line of weakness can enable the portion of the tippingwrapper that circumscribes the tobacco rod to buckle or otherwise deformwhen the consumer presses the lit end of the smoking article against thebase of an ashtray or other hard non-flammable surface to extinguish it.This deformation can help the lit end of the smoking article and anyunburnt tobacco enter the cavity of the hollow tubular element when theconsumer extinguishes the smoking article. This can increase thelikelihood of any buckling during extinguishment being localised to theportion of the smoking article immediately upstream of the hollowtubular element. As a result, the consumer can use less force toextinguish the smoking article, and be less likely to deform the filterduring extinguishment.

As noted above, the line of weakness is provided to enable the portionof the tipping wrapper that circumscribes the tobacco rod to buckle orotherwise deform when the consumer presses the lit end of the smokingarticle against the base of an ashtray or other hard non-flammablesurface to extinguish it. This can either result in the tipping wrapperseparating along the line of weakness, in which case a portion of thetipping wrapper can also be pushed into the cavity of the hollow tubularelement with the loose tobacco and the lit end of the smoking article.Alternatively, this can result in the portion of the tipping wrapperthat circumscribes the tobacco rod folding along the line of weakness,in which case, the portion of tipping wrapper that circumscribes thetobacco rod will remain attached to the filter and for a sleeve that canhelp guide the lit end of the tobacco rod and any unburnt tobacco intothe hollow tubular element.

As noted above a line of weakness is preferably disposed at, or within 5millimetres upstream of, the interface between the hollow tubularelement and the tobacco rod. In some embodiments, the line of weaknessis disposed at the interface between the hollow tubular element and thetobacco rod. In some alternative embodiments, the line of weakness isdisposed between about 0.5 millimetres and about 5 millimetres upstreamof the interface between the hollow tubular element and the tobacco rod,more preferably between about 1 millimetre and about 2 millimetresupstream of the interface between the hollow tubular element and thetobacco rod.

In some embodiments there is more than one line of weakness disposed at,or within 5 millimetres upstream of, the interface between the hollowtubular element and the tobacco rod. For example, there may be betweenabout two and about five lines of weakness. This may allow greatercontrol over the deformation of the portion of the tipping wrapper thatcircumscribes the tobacco rod.

The line of weakness may be formed in the tipping wrapper before orafter it is wrapped around the tobacco rod and the filter. In someembodiments, the line of weakness is formed in the tipping wrapperbefore it is wrapped around the tobacco rod and filter. This cansimplify the manufacturing process. Appropriate types of lines ofweakness include but are not limited to, embossed lines, debossed lines,creases, lines of perforation holes or combinations thereof.

In some preferred embodiments according to the invention, the line ofweakness comprises a plurality of perforation holes.

The perforation holes may be any size. Preferably the plurality ofperforation holes have a diameter of between about 0.2 micrometres andabout 1.2 micrometers, more preferably between about 0.3 micrometers andabout 1 micrometers, even more preferably, between about 0.5 micrometersand about 0.9 micrometers. In some preferred embodiments, theperforation holes have a diameter of about 0.8 micrometres.

The plurality of perforation holes may be substantially the same size ormay be substantially different sizes. Preferably, the perforation holesare substantially the same size. This can help to encourage the portionof the tipping wrapper that circumscribes the tobacco rod to deformevenly when the smoking article is extinguished. Each perforation holemay have any suitable shape, such as a round or oval shape.

The provision of the line of weakness comprising a plurality ofperforation holes according to the dimensions outlined above can helpensure that the line of weakness will allow the portion of the tippingwrapper that circumscribes the tobacco rod to deform under normalextinguishing conditions while preventing the portion of the tippingwrapper that circumscribes the tobacco rod from deforming before theconsumer chooses to extinguish the smoking article.

In some embodiments of the invention, the smoking article furthercomprises a flavour delivery mechanism configured to release flavourantwhen a consumer extinguishes the smoking article. Preferably, theflavour delivery mechanism is provided on or near the filter portion ofthe smoking article. This can allow at least one of the mainstream smokeor the sidestream smoke to become flavoured or aromatised when thesmoking article is being extinguished. For example, a flavour deliverymechanism provided on the inner surface of the tubular element,configured to release flavorant when a consumer extinguishes the smokingarticle may cause the sidestream smoke to become flavoured or aromatisedwhen the smoking article is extinguished. This can flavour or aromatisethe air surrounding the extinguished smoking article and counter or maskany undesirable smells created by the act of extinguishment.

The flavourant may be in any suitable form, for example the flavourantmaybe a liquid flavorant, a powdered flavorant or combinations thereof.Suitable flavourants include, but are not limited to, materials thatcontain natural or synthetic, menthol, mint, such as peppermint andspearmint, eucalyptus, sage, chocolate, liquorice, citrus and otherfruit flavourants, gamma octalactone, vanillin, ethyl vanillin, breathfreshener flavourants, spice flavourants such as cinnamon, methylsalicylate, linalool, bergamot oil, geranium oil, lemon oil, ginger oil,and tobacco flavourant. Other suitable flavourants may includeflavourant compounds selected from the group consisting of an acid, analcohol, an ester, an aldehyde, a ketone, a pyrazine, combinations orblends thereof and the like. Other suitable flavourants may includeflavourant compounds selected from the group consisting of an acid, analcohol, an ester, an aldehyde, a ketone, a pyrazine, combinations orblends thereof and the like.

The flavour delivery mechanism may have a structure in which astructural material releasably encloses a flavourant or flavourants. Forexample, in some embodiments, the flavour delivery mechanism comprises amatrix structure defining a plurality of domains, the flavourant beingtrapped within the domains until released when a consumer extinguishesthe smoking article.

In some embodiments, the flavour delivery mechanism is provided on thehollow tubular element. For example, the flavour delivery mechanism maybe provided on the inner surface or the outer surface of the hollowtubular element. Preferably, the flavour delivery mechanism is providedon the inner surface of the hollow tubular element, and configured torelease flavorant when a consumer extinguishes the smoking article. Thiscan allow the material that is inserted into the cavity of the hollowtubular element to directly contact the flavour delivery mechanism andcause flavour to be released.

The flavour delivery mechanism may comprise a flavorant on the innersurface of the hollow tubular element. Alternatively or in addition, theflavour delivery mechanism may be provided by a surface treatmentprocess on the inner surface of the hollow tubular element.

As noted above, the smoking article preferably comprises a flavourdelivery mechanism that is configured to release flavourant when aconsumer extinguishes the smoking article. For example, theextinguishment may initiate one or more trigger events that result inthe flavour delivery mechanism releasing flavourant. The one or moretrigger events may be selected from the group consisting of theapplication of frictional force, the addition of moisture, a change ofpH, a temperature increase, and any combination thereof. The applicationof frictional force may include application of frictional force to theinner surface of the hollow tubular element, application of frictionalforce to the outer surface of the tipping paper, or both.

In certain preferred embodiments, the flavour delivery mechanism isconfigured to release flavourant when the tobacco rod is burnt beyond acertain point. In this embodiment, the flavour delivery mechanism may beconfigured to release flavorant in response to a temperature increase.

Alternatively, or in addition, the flavour delivery mechanism isconfigured to release flavourant when the smoking article isextinguished by the consumer by pressing the lit end of the smokingarticle against the base of an ashtray or other hard non-flammablesurface. In this embodiment, the flavour delivery mechanism may beconfigured to release flavorant in response to the application offrictional force on the inner surface of the hollow tubular element.

In some preferred embodiments, the hollow tubular element is preferablyformed from a paper material. More preferably, the hollow tubularelement is formed from a plurality of overlapping paper layers, such asa plurality of parallel wound paper layers or a plurality of spirallywound paper layers. Forming the hollow tubular element from a pluralityof overlapping paper layers can help to improve the buckling strength ofthe hollow tubular element. This means that the hollow tubular elementis less likely to buckle or otherwise deform when the user extinguishesthe smoking article.

Preferably, the hollow tubular element comprises at least two paperlayers. Preferably, the hollow tubular element comprises fewer thaneleven paper layers. This can help to ensure the hollow tubular elementhas an appropriate buckling strength while minimising the amount ofmaterial used in the smoking article.

An exemplary method for forming a tube segment from a plurality ofspirally wound paper layers comprises wrapping a plurality ofsubstantially continuous paper strips in an overlapping manner about acylindrical mandrel. The strips are wrapped in a spiral manner so as toform a substantially continuous tube on the mandrel. The formed tube maybe turned about the mandrel, for example using a rubber belt, so thatthe paper layers are continually drawn and wrapped around the mandrel.The formed tube can then be cut into the required lengths downstream ofthe mandrel.

In embodiments according to the invention, the hollow tubular element isformed from an annular shaped segment of filtration material. Thefiltration material may be any filtration material, such as celluloseacetate. The annular shaped segment of filtration material has a hollowcore extending from the upstream end of the annular shaped segment tothe downstream end of the annular shaped segment. Such a segment may bereferred to as a hollow acetate tube.

Preferably, the filtration material of the annular shaped segment is ofhigh particulate efficiency. Preferably, the filtration material of theannular shaped segment comprises fibres of between approximately 1.5denier per filament (dpf) and approximately 5 dpf, more preferablybetween approximately 1.5 denier per filament (dpf) and approximately 3dpf. In a preferred embodiment, the filtration material of the annularshaped segment comprises fibres of approximately 3.3 dpf.

Preferably, the filtration material of the annular shaped segmentcomprises fibres of between approximately 30,000 total denier (td) andapproximately 50,000 td, more preferably between 35,000 total denier(td) and approximately 50,000 td. In a preferred embodiment, thefiltration material of the annular shaped segment comprises fibres ofapproximately 44,000 td.

Preferably, the hollow tube segment comprises one or more plasticisers.Suitable plasticisers include triacetin, and triethylenglycoldi-acetate. Preferably, the plasticiser is present in the annular shapedsegment in an amount of between about 5 and about 15 percentage weight,more preferably between about 8 and about 12 percentage weight.

The provision of the hollow tubular element being formed from an annularshaped segment of filtration material having the aforementionedparticulate efficiency, fibre denier and plasticiser, can improve thebuckling strength of the hollow tubular element.

Preferably, the hollow tubular element has a thickness (t) perpendicularto the longitudinal direction of the smoking article, and a diameter (D)perpendicular to the longitudinal direction of the smoking article, andwherein the diameter (D) to thickness (t) ratio is less than about 80.Preferably, the hollow tubular element has a diameter (D) to thickness(t) ratio of less than about 75, more preferably, less than about 40.This can increase the buckling strength of the hollow tubular elementwhich may reduce the risk of the hollow tubular element buckling,collapsing or otherwise deforming when the consumer extinguishes thesmoking article. It has been observed that, for a given height, thebuckling strength of hollow tubular elements may be considerablyincreased by decreasing the ratio of D:t. This allows the smokingarticle to be extinguished by a consumer while considerably reducing thechance of the hollow tubular element buckling under the compressiveload. Preferably, the hollow tubular element has an diameter (D) tothickness (t) ratio of greater than about 10, more preferably, greaterthan about 20. This can help to ensure that internal cavity of thehollow tubular element is large enough to receive the lit end of thesmoking article and any unburnt tobacco minimising the likelihood of theash or the lit end coming into contact with a consumer's fingers.

In some embodiments according to the invention, the filter furthercomprises a filter wrapper circumscribing at least the hollow tubularelement and the first segment of filtration material, the filter wrapperbeing disposed between the tipping wrapper, and the hollow tubularelement and the first segment of filtration material. Furthermore, theprovision of a filter wrapper may help prevent the hollow tubularelement and the first segment of filtration material from separating inuse or when the consumer chooses to extinguish the smoking article. Thisis particularly relevant if the hollow tubular element and the firstsegment of filtration material are adhered to the filter wrapper.

Preferably, the filter wrapper circumscribes the full length of thehollow tubular element. Preferably, the filter wrapper circumscribes thefull length of the first segment of filtration material.

Examples of suitable filter wrapper materials include, but are notlimited to, cellulose based materials, paper, cardboard, recon,cellulose based film, and combinations thereof.

Preferably, the tobacco rod comprises tobacco material circumscribed bya tobacco rod wrapper.

Any suitable tobacco material may be used. For example, the tobaccomaterial may comprise tobacco cut filler. Preferably, at the downstreamend of the tobacco rod, the cut filler has a filling power of at leastabout 3.5 cubic centimetres per gram at a reference moisture value of12.5 percent oven volatiles. More preferably, at the downstream end ofthe tobacco rod, the cut filler has a filling power of at least about 4cubic centimetres per gram at a reference moisture value of 12.5 percentoven volatiles. In addition, or as an alternative, at the downstream endof the tobacco rod the cut filler preferably has a filling power of lessthan about 8 cubic centimetres per gram at a reference moisture value of12.5 percent oven volatiles. More preferably, at the downstream end ofthe tobacco rod the cut filler has a filling power of less than about 7cubic centimetres per gram at a reference moisture value of 12.5 percentoven volatiles. In some particularly preferred embodiments, at thedownstream end of the tobacco rod the cut filler has a filling power offrom about 3.5 cubic centimetres per gram to about 8 cubic centimetresper gram at a reference moisture value of 12.5 percent oven volatiles.This can reduce the likelihood of the tobacco cut filler entering thecavity of the hollow tubular element without greatly affecting thecombustion properties of the tobacco rod.

Alternatively, or in addition, the tobacco material may comprise acrimped tobacco cast leaf at the downstream end of the tobacco rod. Thiscan help to stop tobacco material from entering the cavity of the hollowtubular element without greatly affecting the combustion properties ofthe tobacco rod.

The tobacco rod wrapper may comprise any appropriate material.Preferably, the tobacco rod wrapper is formed from cigarette paper.

In some embodiments according to the invention, the filter furthercomprises one or more segments of filtration material downstream fromthe first segment of filtration material.

The one or more segments of filtration material downstream from thefirst segment of filtration material may abut the first segment offiltration material. Alternatively, the one or more segments offiltration material downstream from the first segment of filtrationmaterial may be separated from the first segment of filtration materialby a further component or a cavity.

The first segment of filtration material and the one or more segments offiltration material downstream from the first segment of filtrationmaterial may comprise any suitable filtration material or combination offiltration materials. The type of filtration material may be selected toprovide the desired level of RTD (resistance to draw) during smoking andthe desired level of hardness and ovality after deformation. Examples ofsuitable materials include, but are not limited to, cellulose acetate,cellulose, reconstituted cellulose, polylactic acid, polyvinyl alcohol,nylon, polyhydroxybutyrate, thermoplastic material, such as starch,non-woven materials, longitudinally oriented fibres and randomlyoriented fibres, paper, crepe, PLA fibres, and combinations thereof. Oneor more of the materials may be formed into an open cell structure. Allor part of the first segment of filtration material and the one or moresegments of filtration material downstream from the first segment offiltration material may include activated carbon or other sorbentmaterial. The first segment of filtration material and the one or moresegments of filtration material downstream from the first segment offiltration material may include an adhesive or plasticiser or acombination thereof. The first segment of filtration material and theone or more segments of filtration material downstream from the firstsegment of filtration material may be compressible. The first segment offiltration material and the one or more segments of filtration materialdownstream from the first segment of filtration material may comprisethe same filtration material. Alternatively they may comprise differentfiltration materials. In preferred embodiments, the one or more segmentsof filtration material downstream from the first segment of filtrationmaterial comprises a plug of cellulose acetate tow.

Alternatively, or in addition, the filter comprises a mouth end cavityat its downstream end. The mouth end cavity may abut the first segmentof filtration material. Alternatively, if present, the mouth end cavitymay abut the one or more segments of filtration material locateddownstream of the first segment of filtration material. The mouth endcavity may be formed from a section of spirally wound paper layers.Alternately, or in addition, the mouth end cavity may be formed from anannular section filtration material. Alternately, or in addition, themouth end cavity may be formed by the downstream end of the tippingmaterial.

Preferably, the first segment of filtration material comprises a plug ofcellulose acetate tow.

Preferably, the axial stiffness of the hollow tubular element is greaterthan or equal to the axial stiffness of the tobacco rod. This can reducethe likelihood of the hollow tubular element buckling before the tobaccorod buckles, during extinguishment.

The invention will now be further described, by way of example only,with reference to the accompanying drawings in which:

FIG. 1 shows a smoking article in accordance with an embodiment of thepresent invention

FIG. 1 shows a smoking article 10 having an upstream end and adownstream end and comprising a tobacco rod 11 which is attached at itsdownstream end to an axially aligned filter 12. The tobacco rod 11comprises a charge of cut filler 31 that is circumscribed by a tobaccorod wrapper 32. The filter 12 comprises a hollow tubular element 13 anda single segment of cellulose acetate tow 15 which abuts the hollowtubular element 13. The hollow tubular element 13 abuts the tobacco rod11 such that a cylindrical internal cavity 14 is defined by the innersurface of the hollow tubular element 13, the single segment ofcellulose acetate tow 15 and the tobacco rod 11. The filter 12 and aportion of the tobacco rod 11 are circumscribed by tipping wrapper 16.The length of the portion of the tobacco rod 11 that is circumscribed bytipping wrapper 16 is less than the length of the hollow tubular element13. A line of weakness is provided in the tipping wrapper 16, in theform of a plurality of perforations 17. The plurality of perforationsare located 1 millimetre upstream from the downstream end of the tobaccorod 11. The hollow tubular element 13 and the single segment ofcellulose acetate tow 15, are both circumscribed by a filter wrapper 18that is in turn circumscribed by the tipping wrapper 16.

In use, the consumer lights the upstream end of the tobacco rod 11 anddraws through the downstream end of the single segment of celluloseacetate tow 15. When the consumer chooses to extinguish the smokingarticle 10, the smoking article 10 is held by the filter 12 and the litend of the tobacco rod 11 is pressed against the base of an ashtray orother hard non-flammable surface. When this is done, the tipping wrapper16 will bend or separate along the line of the plurality of perforations17. This helps the lit end of the tobacco rod and any unburnt tobacco tobe pushed into the cavity 14 of the hollow tubular element 13. Thishelps to extinguish the smoking article 10 by preventing oxygen reachingthe lit end of the tobacco rod 11.

1. A smoking article comprising: a tobacco rod; a filter in axialalignment with the tobacco rod; and a tipping wrapper circumscribing atleast a portion of the filter and at least a portion of the tobacco rodto secure the filter in axial alignment with the tobacco rod, whereinthe filter comprises: a hollow tubular element at the upstream end ofthe filter adjacent to the tobacco rod; a first segment of filtrationmaterial downstream from and adjacent to the hollow tubular element; afilter wrapper circumscribing at least the hollow tubular element andthe first segment of filtration material, the filter wrapper beingdisposed between the tipping wrapper, and the hollow tubular element andthe first segment of filtration material; and a mouth end cavity at thedownstream end of the filter.
 2. A smoking article according to claim 1,wherein the hollow tubular element has a thickness (t) perpendicular tothe longitudinal direction of the smoking article of at least 100micrometers.
 3. A smoking article according to claim 1, wherein thehollow tubular element has a length greater than about 4 millimetres. 4.A smoking article according to claim 1, wherein the hollow tubularelement has a length that is greater than or equal to the length of theportion of the tipping wrapper that circumscribes the tobacco rod.
 5. Asmoking article according to claim 1, wherein the tipping wrappercomprises a line of weakness, and wherein the line of weakness comprisesa plurality of perforation holes.
 6. A smoking article according toclaim 1, wherein a flavour delivery mechanism is provided on the innersurface of the hollow tubular element, and configured to releaseflavourant when a consumer extinguishes the smoking article.
 7. Asmoking article according to claim 6, wherein extinguishment initiatesone or more trigger events that result in the flavour delivery mechanismreleasing flavourant, the one or more trigger events being selected fromthe group consisting of the application of frictional force, theaddition of moisture, a change of pH, a temperature increase, and anycombination thereof.
 8. A smoking article according to claim 1, whereinthe hollow tubular element comprises at least two paper layers.
 9. Asmoking article according to claim 1, wherein the hollow tubular elementis formed from a plurality of spirally wound paper layers.
 10. A smokingarticle according to claim 1, wherein the hollow tubular element isformed from an annular shaped segment of filtration material.
 11. Asmoking article according to claim 1, wherein the hollow tubular elementhas a thickness (t) perpendicular to the longitudinal direction of thesmoking article, and a diameter (D) perpendicular to the longitudinaldirection of the smoking article, and wherein the diameter (D) tothickness (t) ratio is less than about
 80. 12. A smoking articleaccording to claim 1, wherein the tobacco rod comprises a crimpedtobacco cast leaf at the downstream end of the tobacco rod.
 13. Asmoking article according to claim 1, wherein the filter furthercomprises one or more segments of filtration material downstream fromthe first segment of filtration material.
 14. A smoking articleaccording to claim 1, wherein the axial stiffness of the hollow tubularelement is greater than or equal to the axial stiffness of the tobaccorod.
 15. A smoking article according to claim 1, wherein the hollowtubular element has a thickness (t) perpendicular to the longitudinaldirection of the smoking article of from about 100 micrometers to about700 micrometers.
 16. A smoking article according to claim 1, wherein thehollow tubular element has a length of from about 3 millimetres to about20 millimetres.
 17. A smoking article according to claim 1, wherein thehollow tubular element is formed from a material with a grammage of fromabout 50 grams per square metre to about 250 grams per square metre. 18.A smoking article according to claim 1, wherein the tobacco rodcomprises tobacco material circumscribed by a tobacco rod wrapper andwherein the tobacco material comprises tobacco cut filler.
 19. A smokingarticle according to claim 2, wherein the hollow tubular element has alength greater than about 4 millimetres.
 20. A smoking article accordingto claim 2, wherein the hollow tubular element has a length of fromabout 3 millimetres to about 20 millimetres.